Alloy steel for structural use 15Cr, 20Cr, 40Cr,…

Features and Applications

Alloy structural steel is extensively utilized for manufacturing various machine components. By incorporating different proportions of Mn, Cr, Ni, Mo, V, and other alloys, the material’s hardenability and tempering properties can be enhanced. One of the typical alloy structural steel produced by Baosteel is Cr-Mo steel, which possesses excellent hardenability, resistance to tempering, and high toughness. On the other hand, Mn-B steel is also a good option for high hardenability alloy structural steel. The addition of a small amount of boron significantly improves the hardenability of the material, making Mn-B steel a cost-effective alternative to other alloy steels in some applications. Premium SUV drive shafts, balance bars, and other automobile parts such as chains, seat adjustment systems, clutch plates, and re-rolling are common areas where Mn-B steels are utilized.

Chemical Composition and Mechanical Properties

Grade	Chemical composition%
Grade	C	Si	Mn	S	P
15Cr	0.12-0.18	0.17-0.37	0.40-0.70	≤0.015	≤0.025
20Cr	0.18-0.24	0.17-0.37	0.40-0.70	≤0.015	≤0.025
40Cr	0.37-0.44	0.17-0.37	0.50-0.80	≤0.015	≤0.025

Grade	Mechanical properties
Grade	Hot-rolled hardnessHV	Annealed hardnessHV	Quenching hardnessHRC
15Cr	≤250	≤170	≥34
20Cr	≤260	≤170	≥35
40Cr	≤300	≤180	≥47

Grade	Chemical composition%
Grade	C	Si	Mn	S	P	Cr	Ni
SNCM220	0.17-0.23	0.15-0.35	0.60-0.90	≤0.015	≤0.025	0.40-0.65	0.40-0.70
H42B	0.37-0.45	0.17-0.37	0.70-1.00	≤0.015	≤0.025	≤0.25	≤0.20
20MnB5	0.17-0.23	≤0.40	1.10-1.40	≤0.015	≤0.025	–	≤0.20
26MnB5	0.23-0.28	≤0.40	1.10-1.40	≤0.015	≤0.025	0.10-0.20	≤0.20
27MnCrB5	0.24-0.30	≤0.40	1.10-1.40	≤0.015	≤0.025	≤0.60	≤0.20
40MnB	0.37-0.44	0.17-0.37	1.10-1.40	≤0.015	≤0.025	–	–
16MnCr5	0.14-0.19	≤0.40	1.10-1.30	≤0.015	≤0.025	0.80-1.10	–

Grade	Mechanical properties
Grade	Hot-rolled hardnessHV	Annealed hardnessHV	Quenching hardnessHRC
H42B	≤300	≤180	≥50
20MnB5	≤270	≤170	≥45
26MnB5	≤280	≤170	≥46
27MnCrB5	≤280	≤170	≥48
40MnB	≤300	≤180	≥50
16MnCr5	≤270	≤170	≥35

Grade	Chemical composition%
Grade	C	Si	Mn	S	P	Cr	Mo
15CrMo	0.12-0.18	0.17-0.37	0.40-0.70	≤0.015	≤0.025	0.80-1.10	0.40-0.55
20CrMo	0.17-0.24	0.17-0.37	0.40-0.70	≤0.015	≤0.025	0.80-1.10	0.15-0.25
30CrMo	0.26-0.34	0.10-0.30	0.40-0.70	≤0.015	≤0.025	0.80-1.10	0.15-0.25
35CrMo	0.32-0.40	0.17-0.37	0.40-0.70	≤0.015	≤0.025	0.80-1.10	0.15-0.25
34CrMo4	0.30-0.37	≤0.40	0.60-0.90	≤0.015	≤0.025	0.90-1.20	0.15-0.30
42CrMo4	0.38-0.45	≤0.40	0.60-0.90	≤0.015	≤0.025	0.90-1.20	0.15-0.30

Grade	Mechanical properties
Grade	Hot-rolled hardnessHV	Annealed hardnessHV	Quenching hardnessHRC
15CrMo	≤260	≤170	≥37
20CrMo	≤270	≤170	≥38
30CrMo	≤300	≤180	≥47
35CrMo	≤310	≤180	≥50
34CrMo4	≤310	≤180	≥50
42CrMo4	≤320	≤180	≥52

Grade	Chemical composition%
Grade	C	Si	Mn	S	P	Cr	Ni
20CrMnTi	0.17-0.23	0.17-0.37	0.80-1.10	≤0.015	≤0.025	1.10-1.30	≤0.20
40CrMn	0.37-0.45	0.17-0.37	0.90-1.20	≤0.015	≤0.025	0.90-1.20	–
50Mn2V	0.48-0.57	≤0.30	1.40-1.80	≤0.015	≤0.025	≤0.30	–

Grade	Mechanical properties
Grade	Hot-rolled hardnessHV	Annealed hardnessHV	Quenching hardnessHRC
20CrMnTi	≤280	≤170	≥36
40CrMn	≤300	≤180	≥48
50Mn2V	≤350	≤180	–

Manufacture process and delivery condition

The BT steels undergo a manufacturing process where they are first killed in an oxygen converter. They are then refined and continuously cast into slabs, which are reheated and rolled into coils using the TMCP rolling process. After passing inspection, the BT steels are delivered in either coil form or as sheets that have undergone powerful leveling and cutting. The delivery condition can be TMCP, quenched, annealed, quenched and tempered, and so on. Additionally, steel plates can be delivered with pretreatments such as blasting, based on the customer’s specifications for processing and distribution services.

If you are interested in our products, please feel free to contact us, we look forward to establishing a long-term cooperative relationship with you and developing together!

Carbon tool steel SAE1078, SK5,…

Alloy tool steel 75Cr1, 8CrV/80CrV2,…

We are looking forward to your message:

Send Request

Find your contact person directly here:

To our locations